{% if page.previous.url %}
<a href="{{ page.root }}{{ page.previous.url }}"><span class="glyphicon glyphicon-menu-left" aria-hidden="true"></span><span class="sr-only">previous episode</span></a>
{% else %}
{% if page.previous.url %}
<a href="{{ page.root }}{{ page.previous.url }}"><span class="glyphicon glyphicon-menu-left" aria-hidden="true"></span><span class="sr-only">previous episode</span></a>
{% else %}